Cooling/heating device

ABSTRACT

A device is provided for cooling or heating vessels and containers for carrying out chemical or physical reactions. The device includes the following components in a vertical direction from top to bottom: a heat-conductive cooling or heating plate; at least one Peltier element equipped with electrical connections; optionally at least one heat-conductive separator plate between two Peltier elements respectively; a heat-conductive thermoblock, through which one or more fluid channels pass, for dissipation and supply of heat from and to the at least one Peltier element; and an external control unit for the at least one Peltier element. The components rest on top of one another and are therefore in direct planar contact with one another.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Section 371 of International Application No.PCT/AT2012/050093, filed Jul. 4, 2012, which was published in the Germanlanguage on Jan. 17, 2013, under International Publication No. WO2013/006878 A1 and the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

The present invention relates to a device for cooling or heating vesselsand containers for carrying out chemical or physical reactions, makinguse of the Peltier effect.

The Peltier effect describes the phenomenon that in a current-carryingpair of thermocouples made of different materials (“Peltier element”),one of the thermocouples becomes cold, while the other one becomes warm.Thus, when using Peltier elements as cooling or heating devices, on theside facing away from the object to be cooled or heated, i.e. the“backside” of the Peltier element, heat has to be withdrawn duringcooling operation, while heat has to be supplied during heatingoperation. Usually, this heat compensation occurs through ambient air.

Various devices using Peltier elements for heating or cooling reactionvessels are known. For example, heating blocks with Peltier modules areavailable from the company Bio Integrated Solutions, Inc., which arecalibrated for use at temperatures between −10° C. and +120° C. (seetheir website: http://www.biointsol.com/products.aspx?product=7).

In patent literature, for example, International patent applicationPublication No. WO 01/05497 A1 and U.S. Pat. No. 4,950,608 each describea cooling or heating device comprising a heat-conductive plate and athermoblock provided with fluid channels as well as elements of aresistance heater and having an external control unit. However, none ofthe two documents mentions a Peltier element.

U.S. patent application publication No. 2008/286171 A1 describes acomparable device, however, mentions additionally that the fluid flowingthrough the channels can be cooled by Peltier elements—which due to thedesign have to be positioned outside.

German published patent application DE 10 2007 057 651 A1 discloses asystem for controlling the temperature of samples consisting of a seriesof heat-conductive sample receiving blocks with a plurality of recessesfor test tubes and temperature control blocks, which preferably containPeltier elements, so that a temperature control block can show a heatingeffect in one direction and simultaneously a cooling effect in anotherdirection. Direct transmission of heat between the temperature controlblocks is not envisaged. The overall temperature of the device is toremain constant, i.e. there is no heat dissipated to the outside norsupplied from the outside, while the Peltier elements alternatelyprovide heating and cooling effects to the samples by switching thecurrent direction.

International patent application Publication No. WO 98/50147 A1discloses a system for carrying out chemical reactions under heating orcooling by Peltier elements. Therein, two Peltier elements are providedon two sides of a reaction block having recesses for samples. BothPeltier elements are in contact with one thermoblock each on the sidefacing away from the reaction block, which thermoblock is to serve asheat storage. During operation, the Peltier elements either transmitheat from the reaction block to the two thermoblocks or vice versa.Again, there is no (substantial) heat withdrawn from the system norsupplied to the same.

German published patent application DE 35 25 860 A1 describes athermostat with a metal block having receptive borings for samplecontainers to which a heating or cooling device in the form of Peltierelements is mounted. Therein, either only one single Peltier element isprovided at the bottom side of the block or additional Peltier elementsare fixed to the sides of the block. The possible temperature rangementioned is −60° C. to +60° C., there is, however, no evidence becausethere are no specific working examples at all.

The disadvantage of embodiments using ambient air is that heatcompensation on the backside of the Peltier element occurs very slowly.By providing fans for air supply the effect can be improved slightly,but the results are not satisfactory, in particular in coolingoperation. That is, the temperatures desired for low-temperaturereactions, for example in chemical laboratories, are not achieved, suchas temperatures in the range of those of ice/saline mixtures, i.e. of−20° C. or below, or those of dry ice freezing mixtures, i.e. in therange of −70° C. In addition, the fans sometimes create a lot of noise.

German published patent application DE 2 013 973 A1 discloses athermostat that can be thermally influenced by several Peltieraggregates arranged side by side. For cooling, a heat exchanger isprovided on the backside of the Peltier aggregates, which can beoperated either by water or air cooling. Here, air cooling is to set inwhen water cooling fails, to which purpose, again, preferably a fan isprovided that can be switched on if needed. This air cooling is toguarantee that “long-term investigations can be conducted withoutcontinuous monitoring, without the risk of interruptions”. Obviously,water cooling (and optionally fan-supported) air cooling are seen asequivalent. The temperatures achievable with such thermostats are notmentioned.

Thus, German published patent application DE 20 13 973 A1 is not able tosolve the above problem of providing low temperatures in a reactionblock by Peltier elements, the optional fan causes a certain noiselevel, and in addition, the thermostat disclosed in that document wouldnot be suitable for continuous operation in the heating mode becauseheat supply from the ambient air is not sufficient for this.

BRIEF SUMMARY OF THE INVENTION

Consequently, the object of the invention was to provide a device bywhich the above problem of being able to cool a reaction block to verylow temperatures and heat it with one and the same device can be solved.

Contrary to the state of the art, the inventors of the present subjectmatter have found out and proven in the course of their research thatwater and air cooling are not equivalent, but that water cooling leadsto substantial improvements in the performance of Peltier elements,especially in cases in which several Peltier elements are arranged sideby side or, in particular, one above the other.

Thus, the invention relates to a device for cooling or heating vesselsand containers for carrying out chemical or physical reactions,including tubular reactors, such as capillary reactors, the devicecomprising the following components in a vertical direction from top tobottom:

-   -   a heat-conductive cooling or heating plate;    -   at least one Peltier element equipped with electrical        connections;    -   optionally at least one heat-conductive separator plate between        each two Peltier elements;    -   a heat-conductive thermoblock, through which one or more fluid        channels pass, for dissipation and supply of heat from and to        the at least one Peltier element; and    -   an external control unit for the at least one Peltier element;        wherein the cooling or heating plate, the Peltier element(s),        the optional separator plate and the thermoblock rest on top of        one another and are therefore in direct, full-faced contact.

By providing a thermoblock with continuous liquid cooling or heating forone or more Peltier elements that are in full-faced contact with thethermoblock and the cooling or heating plate arranged thereabove incombination with the control unit for the supplied electric energy, theperformance of the overall device was improved, as is described indetail in the examples below. Even the simplest embodiment of theinvention with only one single Peltier element provided temperaturesbelow −30° C. during cooling operation.

In addition, temperature changes, for example switching from cooling toheating operation, can be implemented substantially faster with theliquid cooling, in particular when the liquid used as cooling or heatingmedium is precooled or preheated outside of the device, where aircooling or heating would require extensive equipment and entail highcosts because of the substantially poorer thermal properties. Of course,for economic reasons the liquid medium used is preferably water.

Specifically, when several Peltier elements are used, which rest on thethermoblock side by side and/or one on top of the other—the number ofelements arranged side by side or one above the other not beingspecifically limited and depending, among other things, on therespectively desired dimensions and geometry—this temperature can besubstantially shifted further down. With a two-stage embodiment, i.e.with Peltier elements one above the other, cooling temperatures around−70° C. were achieved.

In the latter embodiments with two or more Peltier elements arranged oneabove the other, each Peltier element serves for heat compensation forthe above element. Here, the elements are preferably separated from eachother by a heat-conductive separator plate with which they are indirect, full-faced contact, in order to avoid direct electric contact.

Furthermore, the actual Peltier elements are preferably each embedded ina plate of a material that provides the element with electric insulationagainst the outside and thermal protection against external influences,preferably cork. In addition to the electric insulation, the heat flowis thus concentrated in a vertical direction and the elements areprotected against damage.

According to the present invention, a block can be stacked on thecooling or heating plate, in which one or more recesses for receivingreaction vessels or containers can be provided, or the plate itself is ablock, which again can have corresponding recesses. Consequently, thedevice is adaptable to various reaction vessels and containers with highvariability.

For the purpose of the present invention, reaction vessels andcontainers refers to any receptacle in which chemical or physicalreactions can take place, including sample tubes, flasks, bottles,microtiter plates, tubular or pipe reactors, for example capillaryreactors, etc., without being limited thereto.

In some preferred embodiments of the invention, the chemical or physicalreactions can take place directly in “recesses” of the blocks, i.e. thestackable block or the cooling or heating plate provided as a blockitself can serve as a reaction vessel. Provided as a tubular reactor,i.e. with a more or less thin, continuous channel, the block can serveas a flow-through cell.

The fluid channels in the thermoblock, the recesses in the cooling orheating plate provided as a block or those in a block to be stacked onthe plate are preferably bores or cutouts provided therein. These can beproduced in a simple and inexpensive manner.

The materials for the components of the device are not specificallylimited as long as sufficient heat conduction from one component to theother is guaranteed. In view of heat conductivity, the cooling orheating plate, the thermoblock and optionally the separator plate arepreferably made of aluminum, copper or alloys of these metals, withaluminum and its alloys being particularly preferred. Alloys arepreferably those with non-ferromagnetic alloy partners.

However, in cases in which the cooling or heating plate is provided as areaction block, it can, for example, also consist of other alloys, forexample stainless steel or Hastelloy, of glass or of plastics, forexample polytetrafluoroethylene or polyamide. These are characterized bysubstantially lower heat conductivities than aluminum or copper,however, they are far more inert towards the reactions to be conductedtherein. Optionally, the heat conductivity of the material can beincreased by doping or additives, for example metal powder or chips,which is particularly easy with plastics. The same material options alsoapply to a separate reaction block to be stacked on the plate.

In preferred embodiments of the invention, a heat transfer promotingmedium is provided between individual components of the device in orderto further increase the performance. It is not particularly limited andcan, for example, comprise any known heat conduction paste, fluid andthe like, such as zinc oxide or silicone oils containing aluminum,copper or silver components, without being limited thereto.

Preferably, the individual components resting on top of one another areadhered or screwed, in particular screwed, to each other in order toprevent displacement. When using a heat conducting paste or the like, itcan simultaneously serve as adhesive.

Furthermore, in preferred embodiments of the inventive device, the edgesof the components resting on top of one another are in true alignmentwith each other in order to minimize the surface of the overall deviceand to reduce heat exchange with the environment. The cross-sectionalshape of the device and of the individual components is in general notparticularly limited. Particularly useful, however, are rectangular orsquare shapes because they are easy to manufacture and store as well asa circular shape for reasons of surface minimization. The shape ofeither only the cooling or heating plate or also that of othercomponents can be adapted to conventional laboratory apparatus orreaction vessels.

Also, in preferred embodiments of the device, pipe or tube connectionsare provided at external ends of the fluid channels in the thermoblockin order to guarantee easy and quick start-up and safe operation.

Below, the invention will be described in further detail in specificexemplary embodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the invention,there are shown in the drawings embodiments which are presentlypreferred. It should be understood, however, that the invention is notlimited to the precise arrangements and instrumentalities shown. In thedrawings:

FIG. 1 shows a lateral view of a simple embodiment of the inventivedevice.

FIG. 2 shows an isometric view of the embodiment of FIG. 1.

FIG. 3 shows an isometric exploded view diagonally from above of theembodiment of FIGS. 1 and 2.

FIG. 4 shows an isometric exploded view diagonally from below of theembodiment of FIGS. 1 and 3.

FIG. 5 shows a side view of another embodiment of the inventive device.

FIG. 6 shows an isometric view of another embodiment.

FIG. 7 shows an isometric exploded view diagonally from above of theembodiment of FIG. 6.

FIG. 8 shows an isometric exploded view diagonally from below of theembodiment of FIGS. 6 and 7.

FIG. 9 shows an isometric view of a block for receiving reactionvessels.

FIG. 10 shows an isometric view of a block for receiving tubularreactors.

FIG. 11 shows an isometric view of another block for receiving a tubularreactor.

FIG. 12 shows a graphic representation of the measured values obtainedin Example 1 using a device according to an emodiment of the presentinvention.

FIG. 13 shows a graphic representation of the computer-simulated valuesused in Example 2 for the device from Example 1.

FIG. 14 shows a graphic representation of the computer-simulated valuesof Example 3 for a two-stage device.

FIG. 15 shows a graphic representation of the computer-simulated valuesfor the two-stage device of Example 3 in case of a two-dimensionalsimulation.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a simple embodiment of the cooling/heating device of theinvention. A cooling or heating plate 1 is shown at the top, in which anopening 10 for receiving a temperature sensor (not shown) is provided,which is, for example,. a simple thermometer or preferably athermoindicator connected with the control unit (not shown) for thePeltier element.

A Peltier element 2 lies under the plate 1, which is provided withelectric connections 7 for connection with the control element.Preferably, the Peltier element is embedded in a plate of a materialthat provides the element with thermal and electric insulation to theoutside, i.e. to the side. To increase the cooling or heatingperformance, one or more further Peltier elements can be provided inaddition to the Peltier element 2 (which is not shown in FIG. 1).

The thermoblock 6 is arranged under the Peltier element 2, whichconsists of two parts in preferred embodiments, i.e. comprises an upperpart 6 a and a lower part 6 b. This facilitates its production becausethe fluid channels 8 running within the thermoblock are easier toproduce by (computer-controlled) milling in only one or in both parts.FIG. 1 shows the inlet and outlet openings of a fluid channel 8.However, a thermoblock can also be provided with several separatechannels to be supplied with a fluid.

Preferably, a heat conducting medium (not shown) is provided between theindividual components 1 to 6 resting on top of one another in order toimprove heat transfer. The edges of the individual components are intrue alignment with each other in order to keep the surface and thus theheat exchange with the environment small.

FIG. 2 shows an isometric view of the same embodiment in which, inaddition to FIG. 1, also an opening 10 for a temperature sensor as wellas screws 11 for a stable connection of the individual components witheach other are shown, wherein the screws are preferably enveloped withsleeves (not shown), for example of polyamide or other plastics, toprovide thermal insulation.

FIG. 3 shows an isometric exploded view diagonally from above of thesame embodiment. In addition to the two previous drawings, this figurefurthermore shows bottom screws 11 as well as the fact that the Peltierelements 2 consist of two parts. That is, the actual Peltier element 2 ais embedded in a plate 2 b of a material, such as plastic or preferablycork, which not only provides the element with external thermal andelectric insulation, but also protects it against mechanical or chemicaldamages.

FIG. 4 shows an isometric exploded view diagonally from below of thesame embodiment again. In addition, a preferred course of the liquidchannel 8 in the interior of the upper part 6 a of the thermoblock maybe seen. Specifically, the channel 8 preferably runs through thethermoblock in a serpentine or meandering manner in order to providegood heat transfer from the thermoblock to the liquid or vice versa. InFIG. 4, it can be seen that the channel enters and leaves thethermoblock 6 on the same side. What is indicated is, assuming thatliquid enters through the opening marked with 8 a into the left half ofthe thermoblock, a meandering course of the channel 8 to the oppositeside, where it switches to the right half of the thermoblock, afterwhich the channel 8 meanders back to the front side and the outletopening 8 b.

FIG. 5 shows a lateral view of a two-stage embodiment of the inventivedevice with two Peltier elements, wherein another Peltier element 4 isprovided between the cooling or heating plate 1 and the Peltier element2 and a heat conducting separating 5 is provided between the Peltierelements. This separator plate avoids direct electrical contact betweenthe Peltier elements 2 and 4 and at the same time promotes heat transferfrom one to the other. In this embodiment, the lower Peltier element 2serves for cooling or heating the upper element 4 and is itself cooledor heated by the again two-part thermoblock 6 a, 6 b.

FIG. 6 shows an isometric lateral view of another two-stage embodimentwith three Peltier elements. In the lower plane, another Peltier element3 is provided in addition to element 2. On these two, a separator plate5 and a central Peltier element 4 rest. This particularly increases heatexchange between the Peltier elements 2 and 3 in the lower plane and thethermoblock.

FIG. 7 shows an isometric exploded view diagonally from above of theembodiment of FIG. 6 in which the preferred two-part design of thePeltier elements 2 to 4, in particular of element 4, is shown. Thelatter again consists of an element 4 a embedded in an insulating plate4 b.

FIG. 8 shows an isometric exploded view diagonally from below of theembodiment of FIGS. 6 and 7. Again, the serpentine or meandering courseof the fluid channel 8 through the thermoblock is indicated.

FIGS. 9 to 11 show possible embodiments of blocks of the inventivedevice for receiving reaction vessels. This can either be a cooling orheating plate provided as a block or a separate “reaction block” to bestacked thereon. In both cases, the respective component is againconnected with one or more components underneath by screws 11 andpreferably has an opening 10 for a temperature sensor.

In FIG. 9, this block 14 has circular recesses 9 in which individualreaction vessels (not shown), such as flasks, bottles, reaction tubesand the like, can be received and thus cooled or heated.

FIG. 10 shows a cylindrical block serving as holder for a tubular orpipe reactor (not shown), for example a capillary reactor. Duringoperation, the latter is simply wrapped around the cylinder. However,embodiments with a partly or completely hollow and not necessarilycylindrical block are also possible, into which reaction vessels, forexample also capillary reactors, can be placed.

FIG. 11 shows a thermoblock with a spiral-shaped recess, for examplecutout, into which a tubular reactor, for example a capillary reactor,can be placed. During operation, such a block can be provided with acover plate in order to prevent heat exchange with the environment andthus guarantee a constant temperature of the reactor. Such a cover platecan be completely planar or also have a recess, which is preferablymirror-inverted with regard to the recess 9 in the block itself and canbe registered with the latter. In this case, the two recesses togetherdefine, as it were, a heating or cooling channel for the tubularreactor, whose entire surface is thus in contact with the block or coverplate, which greatly improves heat transfer. The material of such acover plate is not particularly limited, and in case of a planar plateit can be glass, for example, while a plate provided with a recessmirror-inverted with regard to the block preferably consists of the samematerial as the thermoblock itself, for example aluminum.

As mentioned above, such blocks can also directly serve as reactionvessels by allowing the chemical or physical reactions to be thermallyinfluenced in corresponding hollow spaces, for example recesses 9, ofthe reaction block.

EXAMPLES Examples 1 and 2 One-Device Stage

A device as shown in FIGS. 1 to 4 was, on the one hand, produced andtested in cooling operation as described below (Example 1), on the otherhand its performance was theoretically calculated in a computersimulation (Example 2).

Example 1

Cooling plate: aluminum, 10×10×1 cm, 3.5 cm Ø bore for a temperaturesensor

Peltier element: TEC2H-62-62-437/75 from Eureca Messtechnik GmbH,Cologne, Germany, embedded in a cork plate with 10×10×0.3 cm

Thermoblock: aluminum, 10×10×2+1 cm height; a serpentine fluid channelwith a width of 6 mm, a depth of 15 mm and an overall length of 547 mmmilled therein, 3.5 cm Ø bore for a temperature sensor

Screwing: 17 (8+9) screws of stainless steel insulated with polyamidesleeves

Temperature sensor: digital laboratory thermometer (2×), Fluke 54-II-Bdifferential thermometer with 2×80PK-25 or 2×80PT-25 temperature probes

Power supply: Current strength-controlled operation, high-performancepower supply for at least 25 V/25 A

The entire device (with exception of the control unit) was envelopedwith polystyrene foam for thermal insulation, and the thermoblock wassupplied with tap water with a temperature of 10-12° C. Subsequently,the power supply to the Peltier element was activated, and the currentstrength was increased in steps of 1 A. After each 5 min equilibrationtime, the temperature of the cooling plate and of the thermoblock wasmeasured at the respective current strength, i.e. between 0 and 20 A, bythe two thermometers. The measured values thus obtained were taken astemperature of the cold side “Tc” or temperature of the warm side “Th”of the Peltier element.

FIG. 12 shows the values thus obtained with the correspondingcompensation curves and their calculation principle.

The lowest, continuously obtained temperature of the cooling plate at acurrent strength of 20 A was −31° C., which required a power of 330 W.For a short time, a temperature of −35° C. was measured at a currentstrength of 25 A, however, due to the power limit of the power supplyused in the experiment, it could not be permanently verified. However,from the compensation curve it can be estimated that with acorresponding current strength, the lower temperature should beachievable continuously.

In any case, the present invention provides a cooling device that iswell suited for the use with low-temperature reactions.

Example 2

For verification of the theoretic power limit of the inventive device ofExample 1 in cooling operation, a computer simulation was conducted byusing the following equation. Here, the temperature differences createdby the thermopower (as defined by the Seebeck coefficient), the heatquantity created by the flow of current and the heat loss caused by theheat transfer between the cold and the warm site of the Peltier elementwere taken into account as follows and dynamically adapted depending onthe respective temperature:

$Q = {\left( {{Se} \times I \times T} \right) - \left( \frac{R \times I^{2}}{2} \right) - \left( {K \times \Delta \; T} \right)}$

Q=refrigerating capacity [W]

Se=Seebeck coefficient [° K/W]

I=current strength [A]

T=temperature in the Peltier element [° K]

R=ohmic resistance of the Peltier element [S2]

K=thermal conductance of the Peltier element [W/° K]

ΔT=temperature difference between warm and the cold side of the Peltierelement [° K]

The following coefficients were used for the calculation according tothe data sheet of the Peltier element used:

Se(300° K)=0.0826 V/° K

R(300° K)=0.815 S2

K(300° K)=3.47 W/° K

Since the three coefficients above depend on the temperature in thePeltier element, the temperature dependency described in the data sheetwas approximated by a fourth-degree polynomial function, which gave thefollowing coefficients:

a b c d e Se(T) −1.385E−10 +1.457E−07 −5.812E−05 +1.060E −02−6.764E−01R(T) +1.260E−08 −1.348E−05 +5.378E−03 −9.445E −01+6.208E+01 K(T)+1.074E−08 −7.837E−06 +1.712E−03 −7.149E−02  +−4.568E+00

For the temperature range of 225° K to 300° K, the R² obtained wasgreater than 0.999.

First, Se, R and K were determined for the corresponding temperature(here T was used for the temperature on the warm side), because it isthe only one known and the cold side temperature would result in acircular definition. The ΔT values were calculated by insertion into thePeltier equation. The working voltage U [V] was calculated by adding theSeebeck term and the relation U=R×I (Ohm's law).

This gave the values shown in the following Table 1:

TABLE 1 I Th Th Se(T) R(T) K(T) dT U Tc Pel Qw Threal [A] [° C.] [°K][V/°K] [Ω] [W/°K] [°K] [V] [° C.] [W] [W] [° C.] 1.0 13.0 286.15 0.08300.807 3.54 −7.4 0.2 20.4 0.2 50.2 13.0 2.0 13.1 286.25 0.0831 0.808 3.54−1.1 1.5 14.2 3.0 53.0 13.1 3.0 13.2 286.35 0.0831 0.808 3.54 4.7 2.88.5 8.4 58.4 13.2 4.0 13.3 286.45 0.0831 0.808 3.54 10.0 4.1 3.3 16.366.3 13.3 5.0 13.5 286.65 0.0831 0.809 3.53 14.9 5.3 −1.4 26.4 76.4 13.56.0 13.8 286.95 0.0832 0.810 3.53 19.5 6.5 −5.7 38.9 88.9 13.8 7.0 14.1287.25 0.0832 0.810 3.53 23.7 7.6 −9.6 53.5 103.5 14.1 8.0 14.4 287.550.0833 0.811 3.53 27.6 8.8 −13.2 70.3 120.3 14.4 9.0 14.8 287.95 0.08330.812 3.52 31.1 9.9 −16.3 89.2 139.2 14.8 10.0 15.2 288.35 0.0834 0.8143.52 34.4 11.0 −19.2 110.0 160.0 15.2 11.0 15.7 288.85 0.0834 0.815 3.5137.4 12.1 −21.7 133.0 183.0 15.7 12.0 16.2 289.35 0.0835 0.817 3.51 40.213.2 −24.0 157.8 207.8 16.2 13.0 16.7 289.85 0.0836 0.818 3.51 42.6 14.2−25.9 184.6 234.6 16.7 14.0 17.3 290.45 0.0837 0.820 3.50 44.9 15.2−27.6 213.3 263.3 17.3 15.0 17.9 291.05 0.0837 0.822 3.50 47.0 16.3−29.1 243.8 293.8 17.9 16.0 18.5 291.65 0.0838 0.823 3.49 48.8 17.3−30.3 276.2 326.2 18.5 17.0 19.2 292.35 0.0839 0.825 3.49 50.4 18.3−31.2 310.5 360.5 19.2 18.0 19.9 293.05 0.0840 0.828 3.48 51.9 19.3−32.0 346.6 396.6 19.9 19.0 20.7 293.85 0.0841 0.830 3.48 53.1 20.2−32.4 384.6 434.6 20.7 20.0 21.5 294.65 0.0842 0.832 3.47 54.2 21.2−32.7 424.3 474.3 21.5 21.0 22.3 295.45 0.0843 0.835 3.47 55.1 22.2−32.8 465.9 515.9 22.3 22.0 23.2 296.35 0.0844 0.838 3.47 55.9 23.2−32.7 509.4 559.4 23.2 23.0 24.1 297.25 0.0845 0.841 3.46 56.5 24.1−32.4 554.6 604.6 24.1 24.0 25.0 298.15 0.0846 0.844 3.46 56.9 25.1−31.9 601.6 651.6 25.0 25.0 26.0 299.15 0.0848 0.847 3.46 57.2 26.0−31.2 650.6 700.6 26.0 26.0 27.0 300.15 0.0849 0.851 3.46 57.3 27.0−30.3 701.4 751.4 27.0 27.0 28.1 301.25 0.0850 0.854 3.46 57.3 27.9−29.2 754.4 804.4 28.1 28.0 29.2 302.35 0.0851 0.859 3.46 57.1 28.9−27.9 809.2 859.2 29.2 29.0 30.3 303.45 0.0852 0.863 3.46 56.8 29.9−26.5 865.9 915.9 30.3 30.0 31.5 304.65 0.0853 0.868 3.47 56.3 30.8−24.8 924.9 974.9 31.5

FIG. 13 shows the values obtained from the simulation with thecorresponding compensation curves. It can be seen that the calculatedvalues match the real values very well. Thus, the temperature measuredfor a short time of the cooling plate in Example 1 at 25 A was −35° C.,and the minimum of the compensation curve is approximately −34° C., witha current strength of approximately 21 A and a power of approximately460 W. And the temperature continuously measured in Example 1 at a powerstrength of 20 A was −31° C., while the simulation gave 32.8° C. Itshould be mentioned that the water temperature in the practicalexperiment varied between 10 and 12° C., while the calculation was basedon a constant temperature of 12° C.

Examples 3 and 4 Two-Stage Device

Similar to Example 2, a computer simulation for an inventive device asshown in FIGS. 6 to 8, i.e. with three Peltier elements arranged side byside or one above the other, was conducted.

Example 3

The calculation of this two-stage embodiment basically followed theone-stage device. First, the current strengths of the primary andsecondary stages, i.e. the two lower Peltier elements 2 and 3 or theupper Peltier element 4, were set as equal, and two data sets, as listedin Example 2 above, were calculated based on the assumption that thewater temperature was 12° C. Here, the cold side temperature of thelower stage corresponded to the warm side temperature of the upperstage.

FIG. 14 shows the values obtained from the simulation with thecorresponding compensation curves. In this case, the minimum of thecompensation curve was approximately −67° C. with a current strength of14 to 15 A and a power of approximately 650 W.

Example 4

Subsequently, the calculation was further optimized by calculating acomplete data set, as listed above in Example 2, at each currentstrength in the primary (lower) Peltier stage for the second (upper)stage, wherein the water temperature was assumed to be 10° C. Due to thelarge data volume, the simulated results are shown only graphically.

FIG. 15 shows a two-dimensional graph showing the current strengths ofthe primary and secondary stages on the x or y axis, and the cold sidetemperature after the second stage, which corresponds to that of thecooling plate of this theoretical two-stage example, i.e. the Tc valueof all secondary stages, on the z axis. With a temperature of −72 ° C.,a maximum was obtained at a current strength of 17 A for the two Peltierelements of the primary stage and of 11.5 A for the secondary stage.This is marked with an paraxial line in the graph.

Thus it is clearly shown that the cooling performance of an inventivedevice using several Peltier elements can be substantially increasedcompared to the one-stage alternative. A two-stage prototypecorresponding to the above simulation is being developed at the moment.If the values that actually measured with this device correspond well tothose simulated in Examples 3 and 4, as was the case in Examples 1 and2, it will prove that a multi-stage device of the invention is avaluable alternative to using dry ice freezing mixtures inlow-temperature reactions in laboratories.

1-14. (canceled)
 15. A device for cooling or heating vessels andcontainers for carrying out chemical or physical reactions, the devicecomprising the following components stacked in a vertical direction fromtop to bottom: a heat-conductive cooling or heating plate; at least onePeltier element equipped with electrical connections; optionally atleast one heat-conductive separator plate between each two Peltierelements; a heat-conductive thermoblock, through which one or more fluidchannels pass, for dissipation and supply of heat from and to the atleast one Peltier element; and an external control unit for the at leastone Peltier element; wherein the components rest one on top of anotherand are therefore in direct, full-faced contact.
 16. The deviceaccording to claim 15, which comprises at least two Peltier elementsresting On the thermoblock side by side.
 17. The device according toclaim 15, which comprises at least two Peltier elements arranged oneabove the other.
 18. The device according to claim 17, wherein aheat-conductive separator plate arranged between the two Peltierelements, both Peltier elements being in direct, full-faced contact withthe separator plate.
 19. The device according to claim 15, wherein theat least one Peltier element is embedded in a plate of a material thatprovides the Peltier element with electric and thermal insulationagainst the outside.
 20. The device according to claim 19, wherein thethermal insulation comprises cork.
 21. The device according to claim 18,wherein at least one of the cooling or heating plate, the thermoblock,and the separator plate is made of aluminum, copper, alloys of thesemetals, stainless steel, Hastelloy, polytetrafluoroethylene, orpolyamide.
 22. The device according to claim 18, wherein the alloys arealloys with non-ferromagnetic alloy partners.
 23. The device accordingto claim 15, wherein the cooling or heating plate comprises a blockhaving recesses for receiving reaction vessels or containers.
 24. Thedevice according to claim 15, wherein the fluid channels in thethermoblock and/or the recesses in the cooling or heating plate arebores or cutouts therein.
 25. The device according to claim 15, furthercomprising a heat transfer promoting medium provided between individualcomponents.
 26. The device according to claim 15, wherein the componentsare screwed to each other.
 27. The device according to claim 15, whereinedges of the components are in true alignment with each other.
 28. Thedevice according to claim 15, further comprising pipe or tubeconnections provided at external ends of the fluid channels.
 29. Thedevice according to claim 15, wherein the fluid channels run through thethermoblock in a serpentine or meandering manner.
 30. The deviceaccording to claim 15, wherein at least one of the components hasopenings for receiving temperature sensors.
 31. The device according toclaim 15, wherein the device is a tubular reactor.
 32. The deviceaccording to claim 31, wherein tubular reactor is a capillary reactor.